I wanted all my brew math in one place so I made this up today.
Figured I would share
If anyone sees something I ****ed up let me know

GRAIN BILL

ORIGINAL TARGET GU * TOTAL VOLUME = TOTAL GU

% OF FERMENTABLE * TOTAL GU = GU OF FERMENTABLE

GU OF FERMENTABLE / EXTRACT POTENTAIL / % EFFCIANCY = LBS

HOPS
The folowing is taken from Designing Great Beers by Ray DanielsTo use this you need the utilazation chart from the book
This is one of many ways to calculate hop bitterness and utilazation.

For wort with over 1.050 gravity during boil , correction factor must be applied

1+[ ( BOIL GRAVITY - 1.050 ) / 2 ] = Cgravity

IBU’s

( WEIGHT OZ. * U% * AA% * 7489 ) / (VOLUME * Cgravity ) = IBU’s

WEIGHT

( VOL * Cgravity * IBU) / ( U% * AA% * 7489 ) = WEIGHT IN OUNCES

*

CAN I MASH IT

( QUARTS PER LB * LBS GRAIN ) / 4 = GALLONS MASH WATER

GALLONS MASH WATER + (.09 * LBS GRAIN ) = VOLUME IN MASH TUN

WATER VOLUMES

PREBOL VOLUME + ( LBS GRAIN * %ABSORBTION ) = TOTAL WATER

(%ABSORBTION I USE IS 0.13 )

TOTAL WATER - [ ( QUARTS PER LB * LBS GRAIN ) / 4 ] = SPARGE
WATER

VOLUME OF GRAINS AND ABSORBED WATER AFTER DRAINING MASH TUN

LBS OF GRAIN ( .09 * ABSORB%) = VOLLUME OF WET GRAIN
I USE THIS TO DETERMINE HOW MUCH ROOM I HAVE FOR BATCH SPARGE ADDITIONS This will vary somewhat depending on kernel size, crush, etc. But it should be a decent starting point. Once you've drained your first runnings, it will over-estimate because of the soluble extract you've removed.